Corey Earl's Taco Chicken Is a Tasty Espressif ESP32 Board for Industrial Control Projects

Maker Corey Earl has designed a feature-packed industrial control and communication board built around the Espressif ESP32-WROOM-32 module: the Taco Chicken.

"I was looking for a way to control and communicate with a solar-powered vehicle weigh scale," Earl explains of the Taco Chicken's origins. "The scale is designed to work on mains (120V) power and be basically constantly powered. We had no easy access to mains power at its location and with the ease and affordability of solar that route was decided upon."

To get the scale working, though, requires a specific boot-up sequence so that the external display can link to the scale itself — and as the scale outputs data over an RS232 serial link, whatever controller was put in place would also need to support that. If that wasn't enough, Earl also needed to monitor the charge levels of 12V batteries connected to the solar panels — and to have a manual start button, should someone tip up for weighing and not have a phone or other Wi-Fi/Bluetooth capable device to hand.

Finding little off-the-shelf that would prove suitable, Earl designed the Taco Chicken. Picking an Espressif ESP32-WROOM-32 module for its relatively high pin count and built-in radio. The resulting control board includes both RS232 and RS485 supprt, four 10A MOSFET outputs with dedicated LED indicators, two DRV8870 motor drivers offering 3.6A each or a combined 7A.

The board also features four analog inputs with filters, I2C on both a D-sub connector and a header designed for use with an optional OLED display, two debounced digital inputs, a third digital input for Dalls One-Wire sensors, and a CH340 USB-UART bridge — plus support for an input voltage of 7-24V.

More information on the Taco Chicken is available on Earl's Hackaday.io page, while the design files and schematics have been published on the Open Source Hardware Lab under the reciprocal GNU General Public License 3.